The utility to perform Exports is 'qemu-img' with the sub-command 'convert'

For example, I currently have a VM Template Image in my GlusterFS storage domain. This storage domain is mounted through the hypervisor "rosie-carreiro", so I first SSH in to the hypervisor, and 'cd' to the path where the RAW template resides.

Using the oVirt admin console, I am able to identify that the template/image has a UUID of, bbb58b82-7252-41e2-9b28-72cbf74d98e4.
There are other CLI tools that allow you to query storage domains and resolve UUIDs to names, however the UI is pretty intuitive for new users.

When you run 'df -h' on an oVirt hypervisor, you can see the mount points used:

NOTE: adapter_type=lsilogic is important because qemu-img VMDK output defaults to using IDE. This means that you cannot later extend the size of the disk in VMware, as the option will actually be grayed out/disabled in vSphere. Use the lsilogic scsi controller format to support extending your disks.